Experimental Study On Consolidation Deformation Of High Filled Loess Fillings

The scale of various infrastructure construction is increasing during the implementati on of the Western Development Strategy and the Belt and Road Strategy.A large nu mber of filling projects have been constructed to meet the shortage of construction lan d,so that many high filling projects with a filling height of 50 meters or even 100 meters have appeared.The post-construction settlement of filled soil becomes a comm on problem in those fill operations.In this paper,the most common fill loess in the northwest region is taken as the research object,and the laboratory test is used as a means to study the consolidation deformation law of the high fill loess body.The mai n research results are as follows:(1)Based on the method of dynamic consolidation of foundations in fill engineering,through dimensional analysis and similar conversion,three different compaction energy corresponding to actual construction is obtained:E1=743.8kJ/m3,E2=1420.8kJ/m3,E3=2169.0kJ/m3.The compaction test of loess was conducted to obtain the compaction characteri stics of remolded loess under different compaction energy.(2)Based on the consolidation compression test,the one-dimensional consolidation cr eep test was carried out on the remolded loess under the condition of optimal water c ontent.Under different compaction energies and different vertical pressures the curves of S and t-S are analyzed to separate the primary and secondary consolidation,and obtain the time point of the boundary between the primary and secondary consolidatio n.According to the test results,the impact of different compaction energies on the co mpressibility of remolded loess was studied,and the relationship between stress-time a nd stress-strain under different additional stresses was analyzed to obtain the remolded loess during the main consolidation stage Deformation law.The rules of the secondary consolidation are obtained under different compaction energies and different vertical pressures according to studying the S,t-S curve and e-lg(t)curve of the secondary co nsolidation stage.(3)Through analyzing the relationship curve between ln(?/t)and ln(t)in the secondar y consolidation stage,a model which describes the deformation characteristics of the s econdary consolidation of the loess is obtained under different compaction energies.It is verified that the model can reflect the deformation law of the high-fill loess during the secondary consolidation stage.The settlement time and final settlement of the high-fill loess can be predicted under different compaction energies and different filling thi cknesses by Combining with the layered sum method.